In these athletes, up to 15% of stress fractures are of the navicular 11. The overall incidence may appear to be increasing due to advances in imaging 9.Īmong track-and-field athletes, up to 21% may experience a stress fracture in the course of a year 10. Because navicular stress fractures are not easily observed on plain radiographs, the reported incidence rates vary widely. Navicular stress fractures may account for up to 35% of stress fractures in athletes. Midfoot fractures only represent a small portion of all foot injuries, though stress fractures comprise approximately one-third of all stress fractures of the foot 8. Both of these joints are crucial for inversion and eversion of the foot. Navicular bone is an essential component of the Chopart joint, which itself consists of the talonavicular and calcaneocuboid joints 7. Some literature suggests a zone of avascularity from the central third to the distal cortex of the navicular, which may contribute to the avascular necrosis sometimes associated with these fractures 6. Supplying the medial plantar aspect of the navicular is a branch of the tibialis posterior artery 6. The dorsal aspect of the navicular receives vascular supply by the medial tarsal branches of the dorsalis pedis artery, along with branches of the lateral tarsal artery 6. At push-off, the transverse tarsal joint is locked and is helpful in forward propulsion. At heel strike, this joint is flexible and plays an important role in absorbing ground impact and accommodating the foot to the ground. The transverse tarsal joint is essential for normal gait and is composed of the talonavicular joint and the calcaneocuboid joint. This arch provides support for normal gait, in particular from mid stance until push-off. The medial longitudinal arch is composed of the navicular, calcaneus, talus, 3 cuneiforms, and 3 medial metatarsals. Considering the large number of articulations found on the various surfaces of the navicular, a large portion of the bone is covered in articular cartilage. The navicular tuberosity, found medially, is the insertion site for the posterior tibial tendon. The largest of these surfaces is found medially with a convex surface, articulating with the medial cuneiform 5. Anteriorly, the navicular has plantar concavity, with there being three articular surfaces 4. Posteriorly, the navicular has a biconcave surface which articulates with the head of the talus 4. The navicular is part of 2 important structures that are essential for normal gait: (1) the medial longitudinal arch and (2) the transverse tarsal joint (also called the midtarsal or Chopart joint). The bone’s major oblique axis lies dorsoplantar and lateromedial, with its base situated dorsolaterally, and its apex plantar medial 4. The navicular is a wedge-shaped bone articulating with the talus, calcaneus, the three cuneiform bones, and the cuboid 4. Navicular fractures often require surgical intervention, though they can be treated conservatively in some cases 1. Navicular fractures are at high risk of nonunion and osteonecrosis owing to the navicular bone’s tenuous blood supply as well as the inherent complexity of the joint 3. Even though midfoot fractures are relatively uncommon injuries, navicular stress fractures represent up to one-third of all stress fractures 2. Navicular fracture also called tarsal navicular fracture, most commonly the result of either traumatic injury or undue stress, with the latter having a higher incidence in younger individuals and athletes 1. Navicular fracture prognosis Navicular fracture
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